Instant messaging (IM) is a service that alerts users when another individual, such as a friend or colleague, is online and allows them to send messages to each other in real time, without the store-and-forward delays inherent in an electronic mail solution. With instant messaging, each user creates a list of other users with whom he or she wishes to communicate (commonly referred to as “buddy lists”). An instant messaging server keeps track of the online status of each of its subscribed users (often referred to as presence information), and when someone from a user's buddy list is online, the service alerts that user and enables immediate contact with the other user.
IM solutions are multiplying quickly and are showing up not only in land-line environments but also in wireless environments used by mobile devices such as cell phones, smart phones, personal data assistants (PDAs), pagers, phone-enabled laptop computers, and other mobile electronic devices. Wireless environments offer the potential for strong IM solutions, based on the time a user carries their mobile device with them. The number of available mobile devices that can run IM solutions is in the hundreds of millions.
It is well known in the art to port IM clients to a mobile device in order to gain access to one of the many IM services available. These services include AOL's Instant Messenger (AIM), ICQ, Yahoo! and Microsoft's MSN Messenger products. These products are known to have tens of millions of users supported by each IM server, and these communities are sometimes inter-connected to produce even larger communities. However, land-line and desktop-based IM solutions falls short of what a user that is often mobile wants and needs, namely good IM functionality wherever they may be with their mobile device. Additionally, the small screens and memories of mobile devices often result in a frustrating experience for people on the road trying to use IM. These people are forced to accept the poor performance and experience of existing IM solutions because they want or need to reach land-line users operating legacy desktop IM solutions and have no other alternatives to select from. There is thus a need for a better and more complete messaging solution (that enables immediate messaging like IM) that is designed for wireless mobile electronic devices that can take advantage of the “always on” nature of a mobile device.
Another problem with existing IM applications is the lack of security. With existing IM applications, it is easy to share the identity of users, meaning that one's identity may be widely disseminated without permission and one might therefore receive messages from an unknown or unwanted source. This leads to a proliferation of junk messages, spam, viruses, and other security concerns. It is also difficult to verify or authenticate the source of an invitation to initiate messaging, which may give rise to impersonation and related security issues.
Another common wireless messaging standard is short message service (SMS), used throughout North America and especially in European China and India. This service also has many flaws. First, the addressing of each SMS user must be performed through their MS-ISDN, or telephone number. This phone number is extremely easy to pass around and it is impossible to verify the authenticity of the sender. Second, there is no implied presence, or any actual delivery information, so the exchange of information has a lot of risk associated with it. SMS also has no concept of a conversation that lasts forever, and in fact there are no SMS devices that keep long-term status information regarding an SMS conversation with another party.
Like reference numerals are used throughout the Figures to denote similar elements and features.